This invention relates to tufting machines and is more particularly concened with the yarn feed mechanism for selectively feeding yarns to the needles of the tufting machine.
In the past, numerous yarn feed mechanisms have been devised, in which one of several frames support yarn feed rolls which are selectivily engaged and disengaged with a drive transmission so as selectively to feed the respective yarns to the needles, according to a prescribed pattern. U.S. Pat. No. 3,847,098 is typical of the type of yarn feed mechanism which feeds the yarns through use of rolls. U.S. Pat. No. 2,862,465 disclosed still another type of yarn feed mechanism in which a plurality of yarn feed rolls are individually clutch controlled by a pattern control mechanism so that each of the plurality feed rolls is driven at different speeds, independently of any of the other feed rolls. Each roll is adapted to control the speed of the yarn to a particular row of stitches within a repeat pattern in order to produce a pattern of high and low loops.
U.S. Pat. No. 3,489,326 disclosed still another form of yarn feed mechanism which employs clutch controlled rolls for selectively feeding the yarn to the needles of the tufting machine. In substantially all of the prior art tufting machines which employ clutch controlled rolls, it is necessary to feed an end of the yarn over one roll and under another in order to thread the machine, because of the drive shafts on which the rolls are disposed.
The present invention disposed the rolls in counterlever fashion on the ends of short drive shafts such that access can be had to each roll by an intermediate portion of a single or several strand of yarns. Thus, the yarns can be disposed over one roll and under another, without the necessity of unthreading the yarn or breaking the yarn.